POS0846 MORTALITY OUTCOME OF ACUTE MYOCARDIAL INFRACTION IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHIES, A QUALITATIVE APPROACH ANALYSIS OF THE NATIONAL INPATIENT SAMPLE FROM 2016-2019
Authors: Z.Y. LI, S. Huang, T. Joshua, D. Dalal, A. Reginato
Journal: Annals of the Rheumatic Diseases (2022)

<h3>Background</h3> The pathophysiology of cardiovascular damage in myositis is a multi-factorial process. Myositis can cause inflammation of the myocardium with accelerated coronary atherosclerosis,the risk of cardiovascular disease in hospitalized patients with idiopathic dermatomyositis was 15% from 2016-17.<sup>1</sup> <h3>Objectives</h3> To investigate the quality of care of acute myocardial infarctions (AMI) events in myositis compared to non-myositis patients across the United States categorized by the types of hospitals, probability of myocardial events, and mortality outcome from the NIS from 2016-19. <h3>Methods</h3> We used SAS statistical software to perform analyses on the NIS database (2016-19) in the US. Adults with AMI and myositis at the time of discharge were identified by International Statistical Classification of Disease 10 (ICD-10) codes. Latent class analysis was used to empirically identify hospital groups across different regions in the U.S where myositis patients received their cardiac care. Once hospital groups were determined, patients were compared with and without myositis in each hospital group. Probabilities of AMI event and mortality among myositis patients were compared using logistic regression analysis. <h3>Results</h3> The NIS sample included 38,363 myositis patients and 24,179,176 non-myositis patients. Three hospital groups were identified, the first two represented inner-city hospitals, with the second group of hospitals tending to be larger and serving lower income patients (Table 1). The third hospital group represented rural hospitals, though they also tended to perform fewer cardiac procedures. Importantly, this third group was about half as likely to identify myositis patients and more likely to identify the unrelated confounder conditions. (myositis=0.10%, confounder=41.0%) This provides evidence that rural hospitals may lack the training and resources to properly care for myositis patients, as hypothesized. Overall, the odd ratio (OR) for myositis patients to have AMI event was 0.83 (<i>p</i> &lt; 0.0001); among those who had AMI events, OR for mortality was 0.60 (<i>p</i> &lt; 0.0001). Patients who received care at more rural hospitals (group 3) were at heightened mortality risk (OR=1.12, <i>p</i> &lt; 0.0001). Opposite to the patient experiences in urban hospitals, the unique risk of mortality to myositis patients in rural hospitals was heightened (OR = 1.88, <i>p</i> &lt; 0.0001). <h3>Conclusion</h3> Myositis was not associated with higher AMI events and mortality outcomes in this nationwide hospitalization cohort. Hospitals in rural locations had fewer diagnosed cases of myositis, catheter procedure and transfer out rate may have contributed to higher AMI mortality outcome in group 3. Further studies should examine if catheter procedure mortality outcome of AMI event in myositis differ in the three hospital groups. <h3>References</h3> [1]Pavon MR, and et al. Reasons for Hospitalization and In-Hospital Mortality in Adults With Dermatomyositis and Polymyositis.2021 Jun 18. J Clin Rheumatol. 2021;10.1097 <h3>Disclosure of Interests</h3> None declared